如何从Graphics g获取像素颜色
在我的学习上，我有图形课程。 我们有Bresenham用于画线和圆形画。 在下一课我将学习洪水填充。 对于洪水填充，我需要获得像素颜色以检查是否需要填充或不填充。 这是我所有课程的代码。
package lab1; import javax.swing.*; import java.awt.*; import java.util.Random; public class Lab1 extends JPanel{ private Random random = new Random(); private boolean isRed; private String s = ""; private int Fill(int x,int y,Graphics g) { if ((x < 0) || (y = 600) || (y >= 600)) return 0; return 0; } private void drawCircle(int centerX,int centerY,int radius, Graphics g) { Graphics2D g2d = (Graphics2D) g; int d = (5 - radius * 4)/4; int x = 0; int y = radius; Color circleColor = Color.white; do { g2d.drawRect(centerX + x, centerY + y, 1,1); g2d.drawRect(centerX + x, centerY - y, 1,1); g2d.drawRect(centerX - x, centerY + y, 1,1); g2d.drawRect(centerX - x, centerY - y, 1,1); g2d.drawRect(centerX + y, centerY + x, 1,1); g2d.drawRect(centerX + y, centerY - x, 1,1); g2d.drawRect(centerX - y, centerY + x,1,1); g2d.drawRect(centerX - y, centerY - x, 1,1); if (d < 0) { d += 2 * x + 1; } else { d += 2 * (x - y) + 1; y--; } x++; } while (x <= y); } public void line(int x,int y,int x2, int y2, Graphics g) { Graphics2D g2d = (Graphics2D) g; //super.paintComponent(g); int w = x2 - x ; int h = y2 - y ; int dx1 = 0, dy1 = 0, dx2 = 0, dy2 = 0 ; if (w0) dx1 = 1 ; if (h0) dy1 = 1 ; if (w0) dx2 = 1 ; int longest = Math.abs(w) ; int shortest = Math.abs(h) ; if (!(longest>shortest)) { longest = Math.abs(h) ; shortest = Math.abs(w) ; if (h0) dy2 = 1 ; dx2 = 0 ; } int numerator = longest >> 1 ; for (int i=0;i<=longest;i++) { g2d.drawRect(x, y, 1, 1); numerator += shortest ; if (!(numerator<longest)) { numerator -= longest ; x += dx1 ; y += dy1 ; } else { x += dx2 ; y += dy2 ; } } } public Lab1() { } public void paintComponent(Graphics g) { Graphics2D g2d = (Graphics2D) g; drawCircle(100,500,50,g); drawCircle(500,500,50,g); g.setColor(Color.red); line(50,450,550,450,g); line(50,450,50,350,g); line(50,350,150,350,g); line(150,350,325,175,g); line(325,175,400,175,g); line(400,175,400,325,g); line(400,325,550,325,g); line(550,325,550,450,g); } //main method: create an instance of TestPanel and output it on a JFrame public static void main(String[] args) { JFrame f = new JFrame(); f.setSize(600, 600); f.setTitle("Sometimes Red, Sometimes Blue"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setContentPane(new Lab1()); f.setVisible(true); } } 如何从x和y获得像素颜色？
而不是我重写已经写的东西，看看这个链接如何着色像素？
您无法从Graphics对象中读取像素 。 图形是绘图的抽象，可能没有像素（想想打印，绘图等）。
您可以创建一个java.awt.BufferedImage并使用其createGraphics（）方法来获取要渲染的Graphics，同时能够使用BufferedImage的getRGB（）方法读取像素以访问像素。
我建议填写BufferedImage。 在那里，您可以使用BufferedImage.getRGB获取每个像素的RGB值